GTT2 (YLL060C) encodes a homodimeric glutathione S-transferase that is phylogenetically related to the zeta class of GSTs. Recombinant Gtt2 conjugates reduced glutathione to the model electrophile 1-chloro-2,4-dinitrobenzene. It is presumed soluble and cytosolic, unlike its ER-associated paralog Gtt1. Strains lacking GTT1 and/or GTT2 are viable but are sensitive to heat shock in stationary phase and grow poorly at high temperature. Gtt1 and Gtt2, with the vacuolar GS-X pump Ycf1, are needed for glutaredoxin-mediated hydroperoxide resistance, consistent with glutathione conjugation and vacuolar sequestration of oxidation products.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0004364 glutathione transferase activity | IBA GO_REF:0000033 | ACCEPT | Summary: IBA from PANTHER PTN000136955 (zeta-class-related GST clade with Arabidopsis GSTZ, E. coli and mammalian donors); Gtt2 groups with the zeta class phylogenetically and has demonstrated GST activity. Supporting Evidence: PMID:9792709 recombinant Gtt1p and Gtt2p exhibit GST activity with 1-chloro-2, 4-dinitrobenzene as a substrate |
| GO:0004364 glutathione transferase activity | IDA PMID:9792709 A novel membrane-bound glutathione S-transferase functions i... | ACCEPT | Summary: Choi et al. 1998: recombinant Gtt2p conjugates GSH to CDNB. Core activity. Supporting Evidence: PMID:9792709 recombinant Gtt1p and Gtt2p exhibit GST activity with 1-chloro-2, 4-dinitrobenzene as a substrate |
| GO:0004364 glutathione transferase activity | IEA GO_REF:0000120 | ACCEPT | Summary: Combined IEA (RHEA:16437, EC 2.5.1.18); consistent with direct evidence. Supporting Evidence: file:yeast/GTT2/GTT2-uniprot.txt Reaction=RX + glutathione = an S-substituted glutathione + a halide PMID:9792709 recombinant Gtt1p and Gtt2p exhibit GST activity with 1-chloro-2, 4-dinitrobenzene as a substrate |
| GO:0004364 glutathione transferase activity | RCA GO_REF:0000123 | ACCEPT | Summary: YeastPathways GLUT-REDOX2-PWY assigns Gtt2 to GSH + RX -> GS-conjugate + HX (EC 2.5.1.18); correct. Supporting Evidence: PMID:9792709 recombinant Gtt1p and Gtt2p exhibit GST activity with 1-chloro-2, 4-dinitrobenzene as a substrate |
| GO:0005737 cytoplasm | IBA GO_REF:0000033 | ACCEPT | Summary: IBA from the GST zeta-related clade (is_active_in cytoplasm). Gtt2 has no targeting signal and is presumed soluble cytoplasmic; consistent with its function. Supporting Evidence: PMID:9792709 recombinant Gtt1p and Gtt2p exhibit GST activity with 1-chloro-2, 4-dinitrobenzene as a substrate |
| GO:0005739 mitochondrion | HDA PMID:14576278 The proteome of Saccharomyces cerevisiae mitochondria. | KEEP AS NON CORE | Summary: Detected in the mitochondrial proteome of Sickmann et al. 2003. No targeting presequence or functional mitochondrial role is known; retained as HTP localisation. Supporting Evidence: PMID:14576278 The proteome of Saccharomyces cerevisiae mitochondria. |
| GO:0005739 mitochondrion | HDA PMID:16823961 Toward the complete yeast mitochondrial proteome: multidimen... | KEEP AS NON CORE | Summary: Detected in the mitochondrial proteome of Reinders et al. 2006; HTP only, no functional mitochondrial role known. Supporting Evidence: PMID:16823961 Toward the complete yeast mitochondrial proteome |
| GO:0005829 cytosol | RCA GO_REF:0000123 | ACCEPT | Summary: YeastPathways reaction compartment cytosol; plausible for this soluble GST. Supporting Evidence: PMID:9792709 recombinant Gtt1p and Gtt2p exhibit GST activity with 1-chloro-2, 4-dinitrobenzene as a substrate |
| GO:0006749 glutathione metabolic process | IBA GO_REF:0000033 | ACCEPT | Summary: IBA (PTN000136307) for glutathione metabolic process, with Gtt2 as donor; GSH conjugation is part of glutathione metabolism. Supporting Evidence: PMID:9792709 recombinant Gtt1p and Gtt2p exhibit GST activity with 1-chloro-2, 4-dinitrobenzene as a substrate |
| GO:0006749 glutathione metabolic process | IDA PMID:9792709 A novel membrane-bound glutathione S-transferase functions i... | ACCEPT | Summary: Choi et al. 1998: GSH-conjugating activity of Gtt2p. Supporting Evidence: PMID:9792709 recombinant Gtt1p and Gtt2p exhibit GST activity with 1-chloro-2, 4-dinitrobenzene as a substrate |
| GO:0006749 glutathione metabolic process | RCA GO_REF:0000123 | ACCEPT | Summary: YeastPathways glutathione-glutaredoxin redox pathway; correct for a GST. Supporting Evidence: PMID:9792709 recombinant Gtt1p and Gtt2p exhibit GST activity with 1-chloro-2, 4-dinitrobenzene as a substrate |
| GO:0043295 glutathione binding | IBA GO_REF:0000033 | KEEP AS NON CORE | Summary: IBA glutathione binding from the zeta-related GST clade. Implicit in transferase activity (GSH is a substrate); retained but less informative than the catalytic term. Supporting Evidence: PMID:9792709 recombinant Gtt1p and Gtt2p exhibit GST activity with 1-chloro-2, 4-dinitrobenzene as a substrate |
Loading supporting content…
Download this section (compressed HTML)Q: Gtt2 groups with the zeta GST class; does it have maleylacetoacetate isomerase or dichloroacetate dehalogenase activity like other zeta GSTs, and what are its endogenous substrates?
Glutathione S-transferase capable of homodimerization; functional overlap with Gtt2p, Grx1p, and Grx2p; protein abundance increases in response to DNA replication stress
Module context: glutathione_thioredoxin_redox_systems; YeastCyc EC 2.5.1.18 — correct.
Loading supporting content…
Download this section (compressed HTML)